The present invention relates to air-conditioning equipment for vehicles, and in particular, to air-conditioning equipment for vehicles, which is applied to cooling, heating, air cleaning and the like for the rear seat, provided on the ceiling surface of a vehicle.
Conventionally, for example, as air-conditioning equipment for the rear seat of a vehicle such as a one-box car or the like, there has been, for example, one which is provided on the ceiling surface and has the following construction (see Japanese Patent Laid-Open Publication No. HEI 1-317819, for example).
According to this air-conditioning equipment for vehicles, as shown in FIG. 12, an inlet port 2 and an outlet port 3 are formed in positions approximately opposite from each other in a casing 1, and a cylindrical impeller 4 is provided inside. On an inner surface of a lower portion of the casing 1 is provided a stabilizer 5 for forming a specified gap between the surface and the cylindrical impeller 4. The shape of the stabilizer 5 is very important in terms of air blowing efficiency and so forth when generating an air flow in an approximately linear direction by the cylindrical impeller 4. For the above reasons, the stabilizer 5 has a construction in which it protrudes in a manner that it comes close to the cylindrical impeller 4 on the inlet port 2 side and the outlet port 3 side and has a recess portion 6 between them, so that angles "a" and "b" between straight lines which connect the center of rotation of the cylindrical impeller 4 and the end portions of the stabilizer 5 and the horizontal plane and the vertical plane fall within respective specified ranges.
Furthermore, in the aforementioned air-conditioning equipment for vehicles, the inlet port and the outlet port are formed in positions approximately opposite from each other in the casing. Inside the casing is provided the cylindrical impeller, and a rear guide and the stabilizer for forming specified spaces between them and the cylindrical impeller are formed on the upper and lower inner surfaces, respectively. On the outlet port side is formed an outlet passage by the casing, the rear guide and the stabilizer. In this outlet passage is pivotally provided a deflecting vane around a pivot axis arranged in a widthwise direction, allowing the direction of air blow to be changed.
However, the aforementioned air-conditioning equipment for vehicles has not sufficiently taken into consideration a surging noise and a whistle noise generated as a consequence of an increase of a ventilation resistance occurring when a cooling performance is improved by reducing a fin pitch (a sectional area in which air can flow) of an evaporator 7, increasing a core thickness (the thickness of a portion through which air passes) or taking a similar measure. That is, the aforementioned air-conditioning equipment for vehicles has merely attempted to increase the fan efficiency by confining the aforementioned angles "a" and "b" in the specified ranges, and the attempt is insufficient in preventing the occurrence of the whistle noise and the surging noise.
Furthermore, in the aforementioned air-conditioning equipment for vehicles, the deflecting vane is provided in the air flow. Therefore, the ventilation resistance increases accordingly as the inclination of the vane relative to the direction of air flow increases, and this becomes a cause for generating a ventilation noise.
Accordingly, it is an object of the present invention to provide air-conditioning equipment for vehicles capable of improving the air blowing performance in the case where the ventilation resistance is increased while maintaining a favorable air blowing state, reducing the occurrence of noises in the air blowing stage and smoothly changing the direction of air blow.